Combination shaft strut and housing



March 3, 1953 HACKER COMBINATION SHAFT STRUT AND HOUSING Filed Jan. 30, 1948 ll 4 i...

INVEN TOR.

j/dC/? m/ Patented Mar. 3, 1953 UNITED STATES PATENT OFFICE COMBINATION SHAFT STRUT AND HOUSING John Louis Hacker, Detroit, Mich.

Application January 30, 1948, Serial No. 5,304

4 Claims. (01. 115-34) This invention relates to marine craft and in particular to propeller shaft housings for such craft. I I

One object of this invention is to provide a combination shaft housing and strut for marine craft which will support and enclose the propeller shaft and at the same time reduce resistance to a minimum as the craft travels through the water.

Another object is to provide a combination shaft housing and strut for marine craft which is attached to the bottom of the hull and which is very efficiently streamlined along both its forward and rearward edges so that greater speed will be obtained than with a conventional exposed shaft and strut, as well as a saving of a great amount of power.

Another object is to provide a combination shaft housing and strut for marine craft which is specially configured to part the water as the craft moves along and to guide the Water rearwardly so that the maximum portion of the water reaches the propeller on the end of the shaft.

Another object is to provide a combination shaft housing and strut for marine craft of the foregoing character which may be either fabricated or cast and which thereby encloses the propeller shaft and at the same time provides the necessary bearing support for the shaft while configured to present the minimum resistance to the water while the craft is in operation.

Another object is to provide a combination shaft housing and strut for marine craft of the foregoing character which also includes a shaft log in a single unit, the shaft housing and strut being streamlined to minimize the resistance thereof.

In the drawing:

Figure 1 is a side elevation of the after portion of the hull of a marine craft showing the combination strut and shaft housing of this invention;

Figure 2 is a bottom plan view of the structure shown in Figure 1;

Figure 3 is a vertical section along the line 3--3 in Figure 1;

Figure 4 is a vertical section along the line 4-4 in Figure 1;

Figure 5 is a vertical section along the line 5-5 in Figure 1;

Figure 6 is a horizontal section along the line 6-6 in Figure 1; and

Figure '7 is a horizontal section along the line 1-'! in Figure l.

Hitherto, in marine craft such as power boats,

the propeller shaft in the conventional form employing an exposed shaft and strut has offered a large amount of resistance as the craft is driven through the water by the propeller. At the same time, the water is diverted by the shaft and strut so that a large proportion of it does not reach the propeller. This, in turn, necessitates the use of propellers of relatively large diameters in order to obtain reasonable efficiency. In particular, a conventional exposed shaft thrusts aside the water leaving a void in its wake which is approx-.- imately four times the diameter of the shaft. The resistance of the conventional shaft and strut, moreover, amounts to ten to fifteen per cent of the resistance of the craft as a whole. This resistance is particularly detrimental in all types of boats, particularly at high speeds, where it actually changes the trim of the boat. In conventional form, the propeller receives only about per cent of the water, the remainder being thrust aside by the resistance of the shaft and the strut.

The present invention provides a combination shaft housing and strut which is so perfectly streamlined that it offers the minimum resistance to the water while the craft is travelling through the water. This results in the fact that the minimum amount of water is thrust aside so that most of the water reaches the propeller allowing the use of a smaller diameter propeller for equal performance with the conventional exposed shaft and strut. The combination shaft housing and strut of the present invention is preferably fabricated or cast in its hollow streamlined form so that it closely hugs the shaft and keeps the breadth of the structure at a minimum. The present invention also contains bearing support for the propeller shaft and it preferably provides a shaft log which is combined with it. A fin to protect the propeller is also optionally provided at the bottom of the structure.

Referring to the drawings in detail, Figure 1 shows a portion of a hull ID of a marine craft, such as a motor boat, having side planking ll, bottom planking l2 and a transom stern l3. The hull I0 is conventional and may be of any suitable type, the type shown being selected merely for purposes of illustration. The hull I0 is provided with a vertically mounted rudder post or shaft 14 which is rotatably mounted in the usual rudder pipe or tube or in a stuffing box (not shown) and at its lower end carries a rudder IS. The hull I0 is propelled by any suitable engine It with or without the usual clutching and reverse gear box I! and having the usual .the shaft [8.

propeller shaft l8 upon the lower end of which is mounted the hub IQ of a propeller 20. All of the foregoing parts are conventional and their details form no part of the present invention.

Secured to the bottom planking I2 is a combination shaft log, housing and strut unit, generally designated 2 I according to a preferred form of the present invention. The unit 2| in turn consists of the shaft log 22 which is joined to or integral with the shaft housing 23. The .shaft log 22 consists of a tubular member 24 through which the propeller shaft 18 passes and which is provided at its upper end with a stuffing box 25 having a gland 26 for compressingia-packing (not shown) around the shaft l8 and thereby preventing leakage along the shaft. Theshaft log 22 at its lower end 2'1 (Figure 3) is secured as by welding or brazing to an elongated mounting plate 28 which extends fore and aft of the bottom planking l2 and which is provided with rows of holes.291fcr receiving'suitablefasteners (not shown). The mounting plate 28 is:of:any suitablesh-ape depending upon'the shape'ofzthe .bottom of the hulllliso as to befairedrsmoothly into the hull on all sides. As the .hull [011s shown, :ior purposes of example, as a V-bottom hull (Figures 3 and 4), the :mountingxplate :28 is ofashallow V-eshaped cross-:sectiontto :merge properly with the .hull. The bottom planking l2 terminates at .the opposite side edges :33 v.of

the mountingplate Hand is fitted into'angle grooves '3! in the keel32, (Figures 3, 4 and;5). The top surface 33 of the mounting plate 28 is configured to fit the bottom surface 734 of the keel 32, the keel 32 being provided with a-clown wardly inclinedbore 35 for the pasage of the shaft log portion'22. The keel32'is also provided with verticalholes 33 for bolts or other fasteners 38a (Figure 3).

l'he mounting plate 28 is provided with a downwardly-extending mid-portion or ridge --3l (Figure 4) which is grooved as at 38 to'receive the'upperedges of side plates 39. Extending downward and rearward from longitudinallyspacedlocations along the mountingplate-Zt in its mid portion 3? are forward and rearward frame members M! and M respectively which meet one another in a bridge portion orjbearing supporting members .42 at theirlower rearward ends. ing plate28, frame members 40 and A I and bridge portion 42 are preferably cast in a single unit so as toprovide strength combined with rigidity. The frame members llland ii are similarly grooved as 3/6113 and 44 respectively i ured) toreceivethe edges of the side plates-39.which aresecuredthereto by suitable fasteners .45.,orby welding or brazing. The forward .orleading edge 46-.of the frame member ifl andthe rearwardor trailing edge 41 of-the frame member 4 l -a-re relatively sharp,-whereas the side plates 39 .are curved outward and also downward'toward one another (Figures 3 to 7 'inclusive) so that -;a streamlined configuration results.

wardly aswell as downwardly towardthe bridge member or bearing supporting -member 42. :A downwardly and rearwardlyeextending fin 5-8 is optionally secured to the frame member Ml-and bearing supporting member 42 to protect the propeller 2B.

Thebearing supporting-member 42is tubular in form (Figure "2) and contains a bore "49 "for The shaft log tubular member 24, mo.unt-

At the same time, the frame members wand 41 sweeprear- It also contains -a.suitable outboard bearing (not shown) for the outer end of the shaft 18. A conventional rubber bearing is suitable for this purpose and, when it is used, the frame member 40 is provided with passageways 50 for admitting water to the rubber bearing in order to lubricate it. The forward and rearward frame members 40 and M and the bearing supporting member 42 cooperate with the mounting plate 28 to form an approximately triangular strut, generally .,designated EI, for the outboard shaft bearing mountedin the bearing supporting member 42.

The foregoing construction thus provides a ccombinati-on ,shaftlog, housing and strut unit which is of streamlined configuration both verticallyandhorizontally and which for this reason greatly reduces the drag of the shaft set up by the resistance of the water as the boat moves through-it. In the case of a speed boat operating at high speeds, of course, the hull planes so that the boat movescalongnear the surface of the water-rather ith'an deeply in it, leaving the propeller 20 and the unit 2| submerged.

WhatI claim is:

'1. :A combination shaft housing and strut for the;shaft and-outboard Shaft bearing of a marine craft, comprising an elongated stream-lined holow -rstructure of approximately the width of a shaft to be housed therein and having substantially sharp forward and rearward edges, said hollow structure including an elongated mounting member adapted to be secured to the bottom of theoraft, a shaft bearing supporting member disposed belowand spaced awayfrom said mounting" member, forward and rearward frame members having their upper ends attached to said mounting member, said rearward framemember havingits upper-end attached to said mounting member at-a place ren'iote from the place of attachine'nt thereto of-the upper end of said forward 'f'rame-memberand also remote from the place of entryof said shaft into-the upper portioriof said hollow structure, said frame member's-converging downwardly and rearwardly from saidmounting membertoward said "bearing supporting member and having their lower ends connected thereto, said frame 'members and said mounting memb-e r'fo'rming an open frame li-lre strut of substantially triangular outline for said outboard shaft bearing, and side plates secured to saidmembers and closing the opposite sides oathsen space of-said strut to form a shaft chamber therein.

:2. A combinationshaft housing and strut for the-shaft and outboard shaft bearing of a marine craft, =-comp'rising' an elongated stream-lined hollow structure of approximately the widthof a shaft to be housed therein and having substantially sharp forward and rearward -edges, said hollow struc ture including anelongated mounting member adaptedto-be'seoured to the bottom of the craft a shaft bearing supporting member disposed below'and spaced away from said mountmg member, forward and rear-ward frame members .of approximately triangular cross-section having their upper ends attached to said mounting member', -said rearward frame member having its upper end attached to said mounting member at a plac'erer'notefrohi the'place of attachment thereto of the upper end of said'for'ward frame member -an'd:also remote from the place of entry of said shaft into the upper portion of :s-aidz-hollowistructure, said frame members converging downwardly and rearwardly from said mounting memberitoward said bearing supporting member and having their lower ends connected thereto, said frame members and said mounting member forming an open frame-like strut of substantially triangular outline for said outboard shaft bearing. and side plates secured to said members and closing the opposite sides of the open space of said strut to form a shaft chamber therein.

3. A combination shaft housing and strut for the shaft and outboard shaft bearing of a marine craft, comprising an elongated stream-lined hollow structure of approximately the width of a shaft to be housed therein and having substantially sharp forward and rearward edges, said hollow structure including an elongated mounting member adapted to be secured to the bottom of the craft, a shaft bearing supporting member disposed below and spaced away from said mounting member, forward and rearward frame members having their upper ends attached to said mounting member, said rearward frame member having its upper end attached to said mounting member at a place remote from the place of attachment thereto of the upper end of said forward frame member and also remote from the place of entry of said shaft into the upper portion of said hollow structure, said frame members converging downwardly and rearwardly from i sides of the open space of said strut to form a shaft chamber therein.

4. A combination shaft housing and strut for the shaft and outboard shaft bearing of a. marine craft, comprising an elongated stream-lined hollow structure of approximately the width of a shaft to be housed therein and having substaning member adapted to be secured to the bottom of the craft and having a longitudinally-extending ridge projecting downwardly therefrom, a shaft bearing supporting member disposed below and spaced away from said mounting member, forward and rearward frame members having their upper ends attached to said mounting member, said rearward frame member having its upper end attached to said mounting member at a place remote from the place of attachment thereto of the upper end of said forward frame member and also remote from the place of entry of said shaft into the upper portion of said hollow structure, said frame members converging downwardly and rearwardly from said mounting member toward said bearing supporting member and having their lower ends connected thereto, said frame members and said mounting member forming an open frame-like strut of substantially triangular outline for said outboard shaft bearing, and. side plates secured to said members and closing the opposite sides of the open space of said strut to form a shaft chamber therein.

JOHN LOUIS HACKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 219,405 Kunstader Sept. 9, 1879 921,913 Thompson May 18,1909

1,446,761 Mix Feb. 27, 1923 1,689,962 Peck Oct. 30, 1928 1,822,272 Decker Sept. 8, 1931 2,076,603 Svendsen Apr. 13, 1937 2,338,796 Berquist Jan. 11, 1944 FOREIGN PATENTS Number Country Date 90,754 France July 25, 1870 15,304 France of 1912 (Add. to Patent 431,862) 

